The present invention concerns a new acidic polycyclic ether antibiotic having the absolute stereochemical formula ##STR1## wherein Me=CH.sub.3 ; pharmaceutically acceptable cationic salts thereof; nutrient feed compositions comprising said antibiotic for poultry, cattle or swine; it use as an anticoccidial agent in poultry, or as a growth promotant in cattle or swine; a fermentation method for its preparation; and the Streptomyces hygroscopicus microorganism which produces said antibiotic in said fermentation method.
The compound (I) is a new member of the acidic polycyclic ether group of antibiotics. This family includes such well known agents as monensin (The Merck Index, 10th Ed., Merck and Co., Inc., Rahway, N.J., 1983, monograph no. 6100), nigericin (loc. cit., monograph no. 6390), narasin (loc. cit., monograph no. 6271), lasalocid (loc. cit., monograph no. 5204), and salinomycin (loc. cit., monograph no. 8193). The subject has been reviewed by Westley, "Polyether Antibiotics", Adv. Appl. Microbiol., vol. 22, pp. 177-223 (1977). These compounds are generally known as coccidiostats and/or as feed additive-growth promotants.